Semiconductor Device Manufacturing Method and Substrate Processing Apparatus

ABSTRACT

Provided is a semiconductor device manufacturing method including: (a) supplying a source gas containing a first element and chlorine to a substrate accommodated in a processing chamber to form an adsorption layer of the source gas on the substrate; (b) supplying a chlorine-containing gas having a composition different from that of the source gas to the substrate while supplying the sources gas before an adsorption of the source gas to the substrate is saturated to suppress the adsorption of the source gas to the substrate; (c) removing the source gas and the chlorine-containing gas remaining on the substrate; (d) supplying a modifying gas including a second element to the substrate to form a layer including the first element and the second element on the substrate by modifying the adsorption layer of the source gas; and (e) removing the modifying gas remaining on the substrate.

CROSS-REFERENCE TO RELATED PATENT APPLICATION

This U.S. non-provisional patent application is a Division of U.S.patent application Ser. No. 13/693,647 filed on Dec. 4, 2012, and claimspriority under 35 U.S.C. §119 of Japanese Patent Application No.2010-128417 filed on Jun. 4, 2010, and International Application No.PCT/JP2011/062381 filed on May 30, 2011, in the Japanese Patent Office,the entire contents of the prior applications is hereby incorporated byreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a semiconductor device manufacturingmethod and a substrate processing apparatus and, more particularly, to asemiconductor device manufacturing method including a process of forminga metal layer on a substrate (wafer) and a substrate processingapparatus.

2. Description of the Related Art

A chemical vapor deposition (CVD) method may be a technique of forming apredetermined film on a substrate. The CVD method includes forming alayer having elements included in source molecules as components in avapor phase or due to a reaction between at least two kinds of sourceson a substrate. There is an atomic layer deposition (ALD) method asanother technique. The ALD method may include alternately supplying atleast two kinds of sources used for forming a film one by one to asubstrate under certain film-forming conditions (temperature and time),adsorbing the sources in units of atomic layers, and forming a film tobe controlled on an atomic level. In the ALD method, processing may beenabled at a lower substrate temperature (processing temperature). Byadsorbing a source gas to a substrate by alternately supplying sourcegases, forming a film may be repeated per single atomic layer, and thethickness of the formed film may be controlled according to the numberof cycles of formation of the film. Also, a titanium nitride (TiN) filmdisclosed in International Patent Publication WO2007/020874 may be takenas an example of a metal film formed on the substrate.

[Patent Document 1] International Patent Publication WO2007/020874

SUMMARY OF THE INVENTION

When a titanium nitride film is formed as a metal layer on a processedsubstrate, there may be cases in which, for example, titaniumtetrachloride (TiCl₄) is used as a titanium (Ti)-containing source andammonia (NH₃) is used as a nitridation gas. However, when the titaniumnitride film is formed using a CVD technique, a rise in resistivity maybe caused due to the fact that chloride (Cl) easily diffuses into thefilm, as compared with when a titanium nitride film is formed using anALD technique.

Meanwhile, a continuous film of the titanium nitride film formed usingan ALD technique may obtain a smooth surface and have a low chlorineconcentration and a relatively low resistance, as compared with atitanium nitride film formed using a CVD technique. However, with animprovement in required performance of the titanium nitride film, it isnecessary to further improve the quality of the titanium nitride film byreducing impurities or lowering resistance.

The above-described example is not limited to the titanium nitride filmbut becomes generally problematic in forming a metal compound. Forexample, when a high-k dielectric metal oxide film is formed using anorganic metal material, problems such as deterioration of tolerance toinsulation may become obvious due to carbon (C) remaining in the film.

Accordingly, the present invention provides a semiconductor devicemanufacturing method and a substrate processing apparatus, which solvethe above-described problem so that a metal film with a low resistivitycan be formed due to a high density and a low source-induced dopantconcentration.

According to one aspect of the present invention, there is provided asemiconductor device manufacturing method including: (a) supplying asource gas containing a first element and chlorine to a substrateaccommodated in a processing chamber to form an adsorption layer of thesource gas on the substrate; (b) supplying a chlorine-containing gashaving a composition different from that of the source gas to thesubstrate while supplying the sources gas before an adsorption of thesource gas to the substrate is saturated to suppress the adsorption ofthe source gas to the substrate; (c) removing the source gas and thechlorine-containing gas remaining on the substrate; (d) supplying amodifying gas including a second element to the substrate to form alayer including the first element and the second element on thesubstrate by modifying the adsorption layer of the source gas; and (e)removing the modifying gas remaining on the substrate.

According to another aspect of the present invention, there is provideda semiconductor device manufacturing method including: (a) supplying asource gas containing a first element and chlorine to a substrateaccommodated in a processing chamber to form an adsorption layer of thesource gas on the substrate; (b) supplying a chlorine-containing gashaving a composition different from that of the source gas to thesubstrate while supplying the sources gas before an adsorption of thesource gas to the substrate is saturated to suppress the adsorption ofthe source gas to the substrate; (c) removing the source gas and thechlorine-containing gas remaining on the substrate; (d) supplying amodifying gas including a second element to the substrate to form alayer including the first element and the second element on thesubstrate by modifying the adsorption layer of the source gas; (e)removing the modifying gas remaining on the substrate; and (f) supplyingthe modifying gas activated by applying light or plasma to desorb thechlorine-containing gas remaining on the layer including the firstelement and the second element formed on the substrate.

According to still another aspect of the present invention, there isprovided a semiconductor device manufacturing method including: (a)supplying a source gas containing a first element and chlorine to asubstrate accommodated in a processing chamber while heating thesubstrate to be at a first temperature to form an adsorption layer ofthe source gas on the substrate; (b) supplying a chlorine-containing gashaving a composition different from that of the source gas to thesubstrate while supplying the sources gas before an adsorption of thesource gas to the substrate is saturated to suppress the adsorption ofthe source gas to the substrate; (c) removing the source gas and thechlorine-containing gas remaining on the substrate; (d) supplying amodifying gas including a second element to the substrate while heatingthe substrate to be at a second temperature higher than the firsttemperature to form a layer including the first element and the secondelement on the substrate by modifying the adsorption layer of the sourcegas; and (e) removing the modifying gas remaining on the substrate.

According to further another aspect of the present invention, there isprovided a substrate processing apparatus including: a processingchamber configured to accommodate a substrate; a source gas supplysystem configured to supply a source gas containing a first element andchlorine to the substrate; a chlorine-containing gas supply systemconfigured to supply a chlorine-containing gas having a compositiondifferent from that of the source gas to the substrate; a modifying gassupply system configured to supply a modifying gas containing a secondelement to the substrate; an exhaust system configured to exhaust gasesremaining on the substrate; and a controller configured to control thesource gas supply system, the chlorine-containing gas supply system, themodifying gas supply system and the exhaust system to perform: (a)supplying a source gas containing a first element and chlorine to asubstrate accommodated in a processing chamber to form an adsorptionlayer of the source gas on the substrate; (b) supplying achlorine-containing gas having a composition different from that of thesource gas to the substrate while supplying the sources gas before anadsorption of the source gas to the substrate is saturated to suppressthe adsorption of the source gas to the substrate; (c) removing thesource gas and the chlorine-containing gas remaining on the substrate;(d) supplying a modifying gas including a second element to thesubstrate to form a layer including the first element and the secondelement on the substrate by modifying the adsorption layer of the sourcegas; and (e) removing the modifying gas remaining on the substrate.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an inclined perspective view of a schematic construction of asubstrate processing apparatus according to an embodiment of the presentinvention.

FIG. 2 is a schematic construction diagram of an example of a processingfurnace and accompanying members thereof, according to an embodiment ofthe present invention, particularly, a longitudinal sectional view of aprocessing furnace portion.

FIG. 3 is a cross-sectional view taken along a line A-A of theprocessing furnace shown in FIG. 2, according to an embodiment of thepresent invention.

FIG. 4 illustrates a film forming sequence according to a firstembodiment of the present invention.

FIG. 5 illustrates a state of adsorption rate of titanium tetrachloride(TiCl₄) before and after introducing hydrogen chloride (HCl).

FIG. 6 is a diagram for explaining a second embodiment of the presentinvention.

FIG. 7 illustrates a film forming sequence according to a thirdembodiment of the present invention.

FIG. 8 illustrates a film forming sequence according to a fourthembodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, exemplary embodiments of the present invention will bedescribed with reference to the accompanying drawings.

A substrate processing apparatus according to the present embodiment isconfigured as an example of a semiconductor manufacturing apparatus usedto manufacture semiconductor devices (integrated circuits (ICs)).Hereinafter, a case in which a vertical apparatus configured to form afilm on a substrate is used as an example of a substrate processingapparatus will be described. However, the present invention is notlimited to the use of the vertical apparatus and a sheet-fed apparatusmay be used as an example.

<Overall Construction of Apparatus>

As shown in FIG. 1, in a substrate processing apparatus 1, a cassette100 accommodating a wafer 200, which is an example of a substrate, isused, and the wafer 200 may be formed of a material such as silicon(Si). The substrate processing apparatus 1 includes a case 101, and acassette stage 105 is installed inside the case 101. Due to anin-process conveyance apparatus (not shown), the cassette 100 may beloaded on the cassette stage 105 or unloaded from the cassette stage105.

The cassette stage 105 is loaded by the in-process conveyance apparatussuch that the wafer 200 accommodated in the cassette 100 maintains avertical posture and a wafer entrance of the cassette 100 faces upward.The cassette stage 105 is configured to rotate the cassette 100rightward by an angle of 90° toward the rear of the case 101 in alongitudinal direction such that the wafer 200 accommodated in thecassette 100 has a horizontal posture and the wafer entrance of thecassette 100 faces the rear of the case 101.

A cassette shelf 109 is installed in a about central region of aforward/backward direction of the case 101. The cassette shelf 109 isconfigured in a plurality of stages and a plurality of columns to keep aplurality of cassettes 100. A transfer shelf 123 in which the cassette100 to be conveyed by the wafer transfer mechanism 125 is accommodatedis installed in the cassette shelf 109.

A preliminary cassette shelf 110 is installed above the cassette stage105 and configured to keep the cassette 100 in reserve.

A cassette conveyance apparatus 115 is installed between the cassettestage 105 and the cassette shelf 109. The cassette conveyance apparatus115 includes a cassette elevator 115 a, which is capable of moving upand down with the cassette 100 held, and a cassette conveyance mechanism115 b serving as a conveyance mechanism. Due to continuous operations ofthe cassette elevator 115 a and the cassette conveyance mechanism 115 b,the cassette conveyance apparatus 115 may be configured to convey thecassette 100 among the cassette stage 105, the cassette shelf 109 andthe preliminary cassette shelf 110.

A wafer transfer mechanism 125 is installed behind the cassette shelf109. The wafer transfer mechanism 125 includes a wafer transferapparatus 125 a, which is capable of rotating or directly driving thewafer 200 in a horizontal direction, and a wafer transfer apparatuselevator 125 b configured to move the wafer transfer apparatus 125 a upand down. Tweezers 125 c configured to pick up the wafer 200 areinstalled in the wafer transfer apparatus 125 a. Due to continuousoperations of the wafer transfer apparatus 125 a and the wafer transferapparatus elevator 125 b, the wafer transfer mechanism 125 includes thetweezers 125 c as a transfer unit of the wafer 200 and is configured tocharge the wafer 200 in a boat 217 or discharge the wafer 200 from theboat 217.

A processing furnace 202 configured to anneal the wafer 200 is installedabove a rear unit of the case 101, and a bottom unit of the processingfurnace 202 is configured to be opened and closed off by a furnaceopening shutter 116.

A boat elevator 121 configured to move the boat 217 up and down withrespect to the processing furnace 202 is installed below the processingfurnace 202. An arm 122 is connected to an elevation stage of the boatelevator 121, and a seal cap 219 is horizontally installed at the arm122. The seal cap 219 is configured to be capable of verticallysupporting the boat 217 and covering and closing off the bottom end ofthe processing furnace 202.

The boat 217 includes a plurality of holding members. The boat 217 isconfigured to adjust centers of a plurality of wafers 200 (e.g., about50 to 150 wafers 200) in a vertical direction and hold each of thewafers 200 in a horizontal direction.

A cleaning unit 134 a configured to supply clean air in a purifiedatmosphere is installed above the cassette shelf 109. The cleaning unit134 a comprises a supply fan and a dustproof filter to circulate theclean air inside the case 101.

A cleaning unit 134 b configured to supply clean air is installed at aleft end portion of the case 101. The cleaning unit 134 b also comprisesa supply fan and a dustproof filter to circulate the clean air inperipheral regions, such as the wafer transfer apparatus 125 a or theboat 217. After circulating in the peripheral regions, such as the wafertransfer apparatus 125 a or the boat 217, the corresponding clean airmay be exhausted from the case 101.

<Operation of Process Apparatus>

Next, main operations of the substrate processing apparatus 1 will nowbe described.

When the cassette 100 is loaded on the cassette stage 105 by thein-process conveyance apparatus (not shown), the cassette 100 is loadedsuch that the wafer 200 maintains a vertical posture on the cassettestage 105 and a wafer entrance of the cassette 100 faces upward.Thereafter, the cassette 100 is rotated rightward by an angle of 90°toward the rear of the case 101 in a longitudinal direction such thatthe wafer 200 accommodated in the cassette 100 has a horizontal postureand the wafer entrance of the cassette 100 faces the rear of the case101.

Subsequently, the cassette 100 is automatically conveyed and transmittedto a designated shelf position of the cassette shelf 109 or thepreliminary cassette shelf 110 by the cassette conveyance apparatus 115and temporarily kept on the cassette shelf 109 or the preliminarycassette shelf 110. Thereafter, the cassette 100 is transferred ordirectly conveyed from the cassette shelf 100 or the preliminarycassette shelf 110 to the transfer shelf 123 by the cassette conveyanceapparatus 115.

When the cassette 100 is transferred to the transfer shelf 123, thewafer 200 is picked up from the cassette 100 through the wafer entranceby the tweezers 125 c of the wafer transfer apparatus 125 a and chargedin the boat 217. The wafer transfer apparatus 125 a configured totransmit the wafer 200 to the boat 217 returns to the cassette 100 andcharges a subsequent wafer 200 in the boat 217.

When a predetermined number of wafers 200 are charged in the boat 217, abottom end of the processing furnace 202 is opened by opening thefurnace opening shutter 116 that has closed off the bottom end of theprocessing furnace 202. Afterwards, the boat 217 charged with a group ofwafers 200 is loaded into the processing furnace 202 due to an elevationoperation of the boat elevator 121, and a lower portion of theprocessing furnace 202 is blocked up by the seal cap 219.

After the boat 217 is loaded, the wafer 200 is arbitrarily processed inthe processing furnace 202. Thereafter, the wafer 200 and the cassette100 are unloaded from the case 101 in the reverse order to the abovedescription.

<Construction of Processing Furnace>

Next, the processing furnace 202 applied to the above-describedsubstrate processing apparatus will be described with reference to FIGS.2 and 3.

As shown in FIGS. 2 and 3, a heater 207 serving as a heating apparatus(heating unit) configured to heat the wafer 200 is installed in theprocessing furnace 202. The heater 207 includes an insulation memberhaving a cylindrical shape with blocked top and bottom ends and aplurality of heater wires. The heater 207 has a unit configuration inwhich the heater wires are installed with respect to the insulationmember. A reaction tube 203 formed of quartz and configured to processthe wafer 200 is installed inside the heater 207.

A manifold 209 formed of, for example, stainless steel, is installed ata bottom end of the reaction tube 203 via an O-ring 220 serving as aseal member. A bottom opening of the manifold 209 is hermeticallystopped by a seal cap 219 serving as a stopper via the O-ring 220. Aprocessing chamber 201 is constituted by at least the reaction tube 203,the manifold 209 and the seal cap 219 in the processing furnace 202.

A boat support 218 configured to support the boat 217 is installed atthe seal cap 219. As illustrated in FIG. 1, the boat 217 includes abottom plate 210 fixed at the boat support 218 and a ceiling plate 211disposed above the bottom plate 210, and a plurality of pillars 221 areinstalled between the bottom plate 210 and the ceiling plate 211. Aplurality of wafers 200 are held in the boat 217. The plurality ofwafers 200 maintain a horizontal posture at regular intervals and aresupported by the pillars 221 of the boat 217.

With a plurality of batch-processed wafers 200 stacked in a plurality ofstages with respect to the boat 217, the processing furnace 202 isconfigured such that the boat 217 is supported by the boat support 218and inserted into the processing chamber 201, and the heater 207 heatsthe wafer 200 inserted into the processing chamber 201 to apredetermined temperature.

As shown in FIGS. 2 and 3, two gas supply pipes 310 and 320 [a first gassupply pipe 310 and a second gas supply pipe 320] are connected to theprocessing chamber 201.

A mass flow controller (MFC) 312 serving as a flow-rate controller(flow-rate control unit), a vaporizer 700 serving as a vaporization unit(vaporizing means), and a valve 314 serving as an opening/closing valveare installed in the gas supply pipe 310 in sequential order from anupstream direction. A nozzle 410 [first nozzle 410] is connected to afront end portion of the gas supply pipe 310. The first nozzle 410extends in a vertical direction [the direction in which the wafers 200are stacked] along inner walls of the reaction tube 203 in an arc-shapedspace between the inner walls of the reaction pipe 203 constituting theprocessing chamber 201 and the wafers 200. A plurality of gas supplyholes 410 a configured to supply a source gas are installed in a lateralsurface of the first nozzle 410. Each of the plurality of gas supplyholes 410 a has the same aperture area or different aperture areas froma lower portion thereof to an upper portion and is installed at the sameaperture pitch.

In addition, a vent line 610 and a valve 614 are installed between thevaporizer 700 and the valve 314 in the gas supply pipe 310 and connectedto an exhaust pipe 231 to be described later. Thus, when a source gas isnot supplied to the processing chamber 201, the source gas is suppliedvia the valve 614 to the vent line 610. A first gas supply system(source gas supply system) is mainly constituted by the gas supply pipe310, the MFC 312, the vaporizer 700, the valve 314, the first nozzle410, the vent line 610 and the valve 614.

In addition, a carrier gas supply pipe 510 configured to supply acarrier gas is connected to the gas supply pipe 310. An MFC 512 and avalve 514 are installed in the carrier gas supply pipe 510. A firstcarrier gas supply system (first inert gas supply system) is mainlyconstituted by the carrier gas supply pipe 510, the MFC 512 and thevalve 514.

An MFC 322 serving as a flow-rate controller (flow-rate control unit)and a valve 324 are installed in the gas supply pipe 320 in sequentialorder from an upstream direction. A nozzle 420 [second nozzle 420] isconnected to a front end portion of the gas supply pipe 320. Similarlyto the first nozzle 410, the second nozzle 420 extends in a verticaldirection [the direction in which the wafers 200 are stacked] alonginner walls of the reaction tube 203 in an arc-shaped space between theinner walls of the reaction pipe 203 constituting the processing chamber201 and the wafers 200. A plurality of gas supply holes 420 a configuredto supply a source gas are installed in a lateral surface of the secondnozzle 420. Similarly to the gas supply holes 410 a, each of theplurality of gas supply holes 420 a has the same aperture area ordifferent aperture areas from a lower portion thereof to an upperportion and is installed at the same aperture pitch. A second gas supplysystem (modifying gas supply system, reaction gas supply system) ismainly constituted by the gas supply pipe 320, the MFC 322, the valve324 and the second valve 420.

In addition, a carrier gas supply pipe 520 configured to supply acarrier gas' is connected to the gas supply pipe 320. An MFC 522 and avalve 524 are installed in the carrier gas supply pipe 520. A secondcarrier gas supply system (second inert gas supply system) is mainlyconstituted by the carrier gas supply pipe 520, the MFC 522 and thevalve 524.

In addition, a gas supply pipe 710 is connected to a downstreamdirection of the confluence between the gas supply pipe 310 and thecarrier gas supply pipe 510. An MFC 712 and a valve 714 are installed inthe gas supply pipe 710. A third gas supply system (firstchlorine-containing gas supply system) is mainly constituted by the gassupply pipe 710, the MFC 712 and the valve 714.

Furthermore, a gas supply pipe 720 is connected to a downstreamdirection of the confluence between the gas supply pipe 320 and thecarrier gas supply pipe 520. An MFC 722 and a valve 724 are installed inthe gas supply pipe 720. A fourth gas supply system (secondchlorine-containing gas supply system) is mainly constituted by the gassupply pipe 720, the MFC 722 and the valve 724. According tocircumstances, the fourth gas supply system may not be installed.

For example, when a source supplied through the gas supply pipe 310 is aliquid, the source is confluent with the carrier gas supply pipe 510 andalso confluent with the gas supply pipe 710 through the gas supply pipe310 via the MFC 312, the vaporizer 700 and the valve 314, and a reactivegas is supplied into the processing chamber 201 via the first nozzle410. For example, when a source supplied through the gas supply pipe 310is a gas, the MFC 312 is replaced by an MFC for gases so that thevaporizer 700 may not be required. Also, the source is confluent withthe carrier gas supply pipe 520 and also confluent with the gas supplypipe 720 via the MFC 322 and the valve 324 through the gas supply pipe320, and a reactive gas is supplied into the processing chamber 201 viathe second nozzle 420.

In one example of the above-described construction, a metal sourceserving as a source gas, for example, a titanium (Ti)-containing source[TiCl₄, tetrakis-dimethylamino titanium (TDMAT, Ti[N(CH₃)₂]₄) andtetrakis(diethylamino) titanium (TDEAT, Ti[N(CH₂CH₃)₂]₄)] is introducedinto the gas supply pipe 310. An oxygen (O)-containing gas or a nitrogen(N)-containing gas serving as a modifying gas for modifying the sourcegas, for example, a nitridation source, such as ammonia (NH₃), nitrogen(N₂), nitrous oxide (N₂O), or monomethyl hydrazine (CH₆N₂), isintroduced into the gas supply pipe 320. A chlorine (Cl)-containing gasserving as a reactive gas for causing a reaction with the source gas,for example, hydrogen chloride (HCl) or chlorine (Cl₂), is introducedinto the gas supply pipes 710 and 720.

An exhaust pipe 231 configured to exhaust the atmosphere of theprocessing chamber 201 is installed in the reaction tube 203. A vacuumpump 246 serving as a vacuum exhaust apparatus (exhaust unit) isconnected to the exhaust pipe 231 via a pressure sensor (not shown)serving as a pressure detector (pressure detection unit) configured todetect the pressure of the processing chamber 201 and an auto-pressurecontroller (APC) valve 243 serving as a pressure regulator (pressureregulating unit). The vacuum pump 246 is configured to vacuum-exhaustthe processing chamber 201 such that an inner pressure of the processingchamber 201 reaches a predetermined pressure (degree of vacuum). Anexhaust system is mainly constituted by the exhaust pipe 231, the APCvalve 243, the vacuum pump 246 and the pressure sensor.

A temperature sensor 263 serving as a temperature detector is installedin the reaction tube 203. The temperature sensor 263 is configured toadjust a state of application of current to the heater 207 based ontemperature information detected by the temperature sensor 263 such thatthe inner temperature of the pressure chamber 201 has a desiredtemperature distribution. The temperature sensor 263 is configured in anL shape like the nozzles 410 and 420 and installed along the inner wallof the reaction tube 203.

A boat 217 is installed in a central portion of the reaction tube 203. Aboat rotation mechanism 267 configured to rotate the boat 217 to improveprocessing uniformity is installed in a bottom end unit of the boatsupport 218 configured to support the boat 217. A rotation axis 255 ofthe boat rotation mechanism 267 is connected to the boat 217 through theseal cap 219 and configured to rotate the boat 217 to rotate the wafer200. The seal cap 219 is configured to move up and down in a verticaldirection due to a boat elevator 121 installed outside the reaction tube203 so that the boat 217 can be loaded into and unloaded from theprocessing chamber 201.

Each of members, such as the MFCs 312, 322, 512, 522, 712 and 722, thevalves 314, 324, 514, 524, 614, 714 and 724, the heater 207, thetemperature sensor 263, the vacuum pump 246, the pressure sensor, theAPC valve 243, the boat rotation mechanism 267 and the boat elevator121, is connected to the controller 280. The controller 280 is anexample of a control unit (control means) configured to control theoverall operation of the substrate processing apparatus 1. Thecontroller 280 is configured to control each of operations of adjustingflow rates using the MFCs 312, 322, 512, 522, 712 and 722, operations ofopening and closing off the valves 314, 324, 514, 524, 614, 714 and 724,an operation of adjusting a pressure based on the opening/closing of theAPC valve 243 and the pressure sensor, an operation of adjusting atemperature of the heater 207 based on the temperature sensor 263, anoperation of running and stopping the vacuum pump 246, an operation ofcontrolling a rotation rate of the boat rotation mechanism 267 and anoperation of moving the boat 217 up and down using the boat elevator121.

<Method of Manufacturing Semiconductor Device>

Next, an example of a method of forming an insulating film on asubstrate to manufacture a large scale integrated circuit, as a processof manufacturing a semiconductor device, using the processing furnace202 of the above-described substrate processing apparatus will bedescribed. In the following description, an operation of each of unitsof the substrate processing apparatus is controlled by the controller280.

First Embodiment

In the present embodiment, a method of forming a titanium nitride filmas a metal film on a substrate will now be described. In the presentembodiment, an example of a process using TiCl₄ gas as a titanium(Ti)-containing source serving as a source gas, NH₃ gas as a nitridationgas serving as a modifying gas, and HCl as a chlorine-containing gasserving as a reactive gas will be described.

FIG. 4 illustrates a film forming sequence according to a firstembodiment of the present invention. In a film forming process, thecontroller 280 may control the substrate processing apparatus 1 as willbe described below. That is, by controlling the heater 207, the insideof the processing chamber 201 is set to a temperature of, for example,about 200° C. to about 650° C., preferably, a temperature of about 300°C. to about 500° C. Thereafter, a plurality of wafers 200 may be chargedin the boat 217, and the boat 217 may be loaded into the processingchamber 201. Afterwards, the boat 217 may be rotated by the boat drivingmechanism 267 to rotate the wafer 20. Thereafter, the inside of theprocessing chamber 201 is vacuum-exhausted by opening the valve 243 withthe vacuum pump 246 operated. A sequence to be described later isperformed with the wafer 200 maintained at a temperature ranging fromabout 200° C. to about 650° C., preferably, about 300° C. to about 500°C.

(Step 11)

Titanium tetrachloride (TiCl₄) is supplied in step 11. Since TiCl₄ is aliquid at room temperature, a method of supplying TiCl₄ into theprocessing chamber 201 may include a process of supplying TiCl₄ aftervaporizing TiCl₄ by heating or a process of allowing an inert gas calleda carrier gas, such as helium (He), neon (Ne), argon (Ar), or nitrogen(N₂), to pass through a TiCl₄ container using the vaporizer 700 andsupplying the vaporized amount into the processing chamber 201 alongwith the carrier gas. However, the latter process will now be describedas an example.

TiCl₄ is supplied to the gas supply pipe 310, and a carrier gas (N₂) issupplied to the carrier gas supply pipe 510. The valve 314 of the gassupply pipe 310, the valve 514 of the carrier gas supply pipe 510 andthe APC valve 243 of the exhaust pipe 231 are opened together. Thecarrier gas is supplied through the carrier gas supply pipe 510 andflow-adjusted by the MFC 512. TiCl₄ is supplied through the gas supplypipe 310, flow-adjusted by the MFC 312, vaporized by the vaporizer 700,mixed with the flow-adjusted carrier gas, supplied into the processingchamber 201 through the gas supply hole 410 a of the nozzle 410, andexhausted through the exhaust pipe 231. In this case, an inner pressureof the processing chamber 201 is maintained within the range of about 20Pa to about 100 Pa, for example, at about 30 Pa, by appropriatelyadjusting the APC valve 243. A flow rate of the supplied TiCl₄ iscontrolled by the MFC 312 to be in the range of about 1.0 g/min to about2.0 g/min. A time taken to expose the wafer 200 to TiCl₄ ranges fromabout 3 seconds to about 10 seconds. A temperature of the heater 207 isset such that the wafer 200 is maintained at a temperature ranging fromabout 200° C. to about 650° C., preferably, about 300° C. to about 500°C., for example, at a temperature of about 380° C.

In this case, only TiCl₄ and inert gases such as N₂ and Ar are suppliedinto the processing chamber 201, and NH₃ and HCl are not supplied.Accordingly, TiCl₄ does not cause a vapor reaction but causes a surfacereaction (chemical adsorption) with the surface of the wafer 200 or anunder film to form an adsorption layer of the source (TiCl₄) or atitanium (Ti) layer (hereinafter, a titanium-containing layer). Theadsorption layer of TiCl₄ includes not only a continuous adsorptionlayer of source molecules but also a discontinuous adsorption layer. TheTi layer includes a discontinuous layer formed of Ti but also a Ti thinfilm obtained by overlapping continuous layers formed of Ti. Also, acontinuous layer formed of Ti may be called a Ti thin film.

Simultaneously, an inert gas is supplied through the carrier gas supplypipe 520 connected to a midway point of the gas supply pipe 320 byopening the valve 524. Thus, TiCl₄ may be prevented from returning tothe side of NH₃.

(Step 12)

HCl is supplied in step 12. HCl serves to inhibit the growth of TiN. HClis supplied to the gas supply pipe 710. The valve 714 of the gas supplypipe 710 is opened. TiCl₄, which is mixed with the carrier gas andsupplied through the gas supply pipe 310, is mixed with HClflow-adjusted by the MFC 712, supplied into the processing chamber 201through the gas supply hole 410 a of the nozzle 410, and exhaustedthrough the exhaust pipe 231.

In this case, an inert gas, such as N₂ gas, is continuously suppliedinto the processing chamber 201 through the gas supply hole 420 a of thenozzle 420.

(Step 13)

The supply of TiCl₄ to the processing chamber 201 is stopped by closingoff the valve 314 of the gas supply pipe 310, and TiCl₄ is supplied tothe vent line 610 by opening the valve 614. Thus, only a mixture of HCland the carrier gas is supplied through the gas supply hole 410 a of thenozzle 410. When HCl is supplied, an inner pressure of the processingchamber 201 is maintained in the range of about 10 Pa to about 50 Pa,for example, at 20 Pa, by appropriately adjusting the APC valve 243. Aflow rate of the supplied HCl is controlled by the MFC 712 to be in therange of about 0.5 slm to about 5 slm. A time taken to expose the wafer200 to HCl ranges from about 1 second to about 5 seconds. A temperatureof the heater 207 is set such that the wafer 200 is maintained at atemperature ranging from about 200° C. to about 650° C., preferably,about 300° C. to about 500° C., for example, at a temperature of about380° C.

(Step 14)

The supply of HCl into the processing chamber 201 is stopped by closingoff the valve 714 of the gas supply pipe 710. In this case, with the APCvalve 243 of the gas supply pipe 231 open, the inside of the processingchamber 201 is exhausted by the vacuum pump 246 until an inner pressureof the processing chamber 201 reaches 10 Pa or lower. Thus, theremaining TiCl₄ is excluded from the processing chamber 201. In thiscase, an inert gas, such as N₂ gas, is continuously supplied into theprocessing chamber 201 through the gas supply hole 420 a of the nozzle420. Thus, the remaining TiCl₄ is excluded more effectively.

(Step 15)

NH₃ is supplied in step 15. NH₃ is supplied to the gas supply pipe 320,and a carrier gas (N₂) is supplied to the carrier gas supply pipe 520.The valve 324 of the gas supply pipe 320, the valve 522 of the carriergas supply pipe 520 and the APC valve 243 of the exhaust pipe 231 areopened together. The carrier gas is supplied through the carrier gassupply pipe 520 and flow-adjusted by the MFC 522. NH₃ is suppliedthrough the gas supply pipe 320, flow-adjusted by the MFC 322, mixedwith the flow-adjusted carrier gas, supplied into the processing chamber201 through the gas supply hole 420 a of the nozzle 420, and exhaustedthrough the exhaust pipe 231. When NH₃ is supplied, an inner pressure ofthe processing chamber 201 is maintained within the range of about 50 Pato about 1000 Pa, for example, at 60 Pa, by appropriately controllingthe APC valve 243. A flow rate of the supplied NH₃ controlled by the MFC324 ranges from about 1 slm to about 10 slm. A time taken to expose thewafer 200 to NH₃ ranges from about 10 seconds to about 45 seconds. Atemperature of the heater 207 is set such that the wafer 200 ismaintained at a temperature ranging from about 200° C. to about 650° C.,preferably, about 300° C. to about 500° C., for example, at atemperature of about 380° C.

Simultaneously, an inert gas, such as N₂, is supplied through thecarrier gas supply pipe 510 connected to a midway point of the gassupply pipe 310 by opening the opening/closing valve 514. Thus, NH₃ maybe prevented from returning to the side of TiCl₄.

By supplying NH₃, a surface reaction (chemical adsorption) occursbetween the titanium-containing layer chemisorbed on the wafer 200 andNH₃ to form a titanium nitride film on the wafer 200.

(Step 16)

In step 16, the supply of NH₃ is stopped by closing off the APC valve324 of the gas supply pipe 320. In this case, with the APC valve 243 ofthe gas supply pipe 231 open, the processing chamber 201 is exhausted toan inner pressure of about 10 Pa or lower by the vacuum pump 246. Thus,the remaining NH₃ is excluded from the processing chamber 201. In thiscase, when an inert gas, such as N₂ gas, is supplied into the processingchamber 201 through each of the gas supply pipe 320 serving as an NH₃supply line and the gas supply pipe 310 serving as a TiCl₄ supply line,the remaining NH₃ is excluded more effectively.

By performing one cycle including steps 11 through 16 at least once, atitanium nitride film is formed to a predetermined thickness on thewafer 200.

As described above, by introducing TiCl₄ into the processing chamber201, TiCl₄ is adsorbed on an adsorption site of the wafer 200 so thatthe surface of the wafer 200 can be slowly coated with TiClx. Although atime taken to coat the surface of the wafer 200 with TiClx depends on anambient temperature, an introduced flow rate, or a pressure, the timeranges from about several seconds to about several tens of seconds.Also, before a time point (saturation point) when TiCl₄ is adsorbed onall adsorption sites, HCl serving as a reaction inhibiting material isintroduced once TiCl₄ has been introduced. The introduced HCl fillsportions of the adsorption sites, thereby hindering the adsorption ofTiCl₄. When comparing an increase rate of the adsorbed amounts of TiCl₄before and after the introduction of HCl, a point of inflection occursin the graph as illustrated in FIG. 5. That is, the introduction of HClleads to a drop in the adsorption rate of TiCl₄. By use of the drop inthe adsorption rate of TiCl₄, the supply of TiCl₄ and HCl is stoppedbefore all absorbable sites of the surface of the wafer 200 are coveredwith TiClx. Thus, the surface of the wafer 200 is covered with oneatomic layer or less of TiCl_(x) having. In this state, impuritiesremaining on the film may be inhibited to a minimum so that a subsequentprocess of growing or modifying a thin film can be finished only bysubstituting some atoms of a polar surface. Next, after purging theremaining TiCl₄ from the processing chamber 201, NH₃ may be introduced.NH₃ may react with TiClx formed on the surface of the processedsubstrate so that TiN can be grown and simultaneously, HCl can bedesorbed from the surface of the substrate. Next, the remaining NH₃ ispurged from the processing chamber 201, and the above-describedprocessing operation is repeated until a desired film thickness isobtained, thereby obtaining a TiN film with good quality.

That is, by supplying HCl as a reaction inhibiting material, the amountof Ti adsorbed on the substrate is reduced, and afterwards, NH₃ issupplied to cause a reaction of Ti with a sufficient amount of nitrogen(N). As a result, an N-richer film may be formed to lower theresistivity of the TiN film.

Second Embodiment

While a film of less than one atomic layer is formed in detail byintroducing a reaction inhibiting material into the processing chamber201 in the first embodiment, a by-product generated by optimizing areactive gas and reaction conditions without introducing the reactioninhibiting material is employed in the second embodiment. For example,the amount of a formed film at a point of inflection may be controlledby controlling a film forming temperature or pressure. The secondembodiment describes an example case in which TiCl₄ is used as atitanium (Ti)-containing gas serving as a source gas and NH₃ is used asa nitridation source serving as a modifying gas. As in the firstembodiment, during a film forming process according to the secondembodiment, the controller 280 controls the substrate processingapparatus 1 as will be described below. That is, the inside of theprocessing chamber 201 is set to a temperature ranging from about 250°C. to about 450° C. by controlling the heater 207, and maintained undera pressure of about 10 Pa to about 100 Pa, and the same process as inthe above-described first embodiment is performed. FIG. 6 illustrates anexample case in which a TiN film is formed under the above-describedconditions. As shown in FIG. 6, it can be seen that a film-formingamount for each film-forming process, which may be obtained by dividinga final film-forming thickness by the number of times films are formedin a series using an introduction time of TiCl₄ for each film-formingprocess as a parameter is less than one atomic layer and notproportional to time even if time is extended. Also, it can be seen thatformation of a film is not saturated in a time region after the point ofinflection. In low-order plane orientation indices, since one atomiclayer of TiN crystals ranges from about 1 Å to about 3 Å, it can be seenin the present example that a film having about 1/10 of an atomic layerto about ¼ of an atomic layer is formed for each series film-formingprocess.

Third Embodiment

In the third embodiment, light or plasma energy is used to activate amodifying gas and desorb a reaction inhibiting material from thesurface. FIG. 7 illustrates a film forming sequence according to a thirdembodiment of the present invention. In the third embodiment, onlydifferent points from the first embodiment will be described.

(Step 21)

In step 21, TiCl₄ is supplied into the processing chamber via the nozzle410 under the same condition as in step 11. In this case, an inert gas,such as N₂, is supplied into the processing chamber via the nozzle 420.

(Step 22)

As in step 12, HCl is supplied into the processing chamber via thenozzle 410 through the gas supply pipe 710 with TiCl₄ supplied into theprocessing chamber. In this case, an inert gas, such as N₂, iscontinuously supplied through the nozzle 420.

(Step 23)

As in step 13, with HCl supplied into the processing chamber, the supplyof TiCl₄ into the processing chamber is stopped by closing off the valve314 of the gas supply pipe 310, and TiCl₄ is supplied to the vent line610 by opening the valve 614.

(Step 24)

As in step 14, the supply of HCl into the processing chamber is stoppedby closing off the valve 714 of the gas supply pipe 710. In this case,with the APC valve 243 of the gas exhaust pipe 231 open, the inside ofthe processing chamber is exhausted to a pressure of about 20 Pa orlower by the vacuum pump 246. Thus, the remaining TiCl₄ is excluded fromthe processing chamber 201. In this case, when an inert gas, such as N₂,is supplied into the processing chamber 201 through the nozzle 420, theremaining TiCl₄ is excluded more effectively.

(Step 25)

In step 25, NH₃ is supplied into the processing chamber under the samecondition as in step 15. NH₃ is supplied into the gas supply pipe 320,and a carrier gas (N₂) is supplied into the carrier gas supply pipe 520.

(Step 26)

In step 26, the supply of NH₃ is stopped by closing off the valve 324 ofthe gas supply pipe 320. Also, the processing chamber 201 is exhaustedto a pressure of about 20 Pa or lower by the vacuum pump 246 with theAPC valve 243 of the gas exhaust pipe 231. Thus, the remaining NH₃ isexcluded from the processing chamber 201.

(Step 27)

In step 27, light or plasma is irradiated while supplying NH₃ into theprocessing chamber again. For example, NH₃ is supplied under the sameconditions as in steps 15 and 25.

(Step 28)

In step 28, the supply of NH₃ is stopped by closing off the valve 324 ofthe gas supply pipe 320. Also, the processing chamber 201 is exhaustedto a pressure of about 20 Pa or lower by the vacuum pump 246 with theAPC valve 243 of the gas exhaust pipe 231 open. Thus, the remaining NH₃is excluded from the processing chamber 201.

By performing one cycle including steps 21 through 28 at least once apredetermined number of times, a titanium nitride film is formed to apredetermined thickness on the wafer 200. As described above, desorptionof a reaction inhibiting material is promoted by applying light orplasma. Also, NH₃ is introduced so as to enable nitridation even ifunreacted Ti is dispersed. Although the third embodiment describes acase in which application of light or plasma and introduction of NH₃ areperformed simultaneously, the application of light or plasma and theintroduction of NH₃ may not necessarily be performed simultaneously.

Fourth Embodiment

As in the above-described third embodiment, in the fourth embodiment,thermal energy is used to activate a modifying gas and desorb a reactioninhibiting material from the surface. FIG. 8 illustrates a film formingsequence according to a fourth embodiment of the present invention. Inthe fourth embodiment, only different points from the first embodimentwill be described.

(Step 31)

In step 31, TiCl₄ is supplied into the processing chamber under the samecondition as in step 11. A temperature of the heater 207 is set suchthat the wafer 200 is maintained at a temperature ranging from about200° C. to about 550° C., preferably, about 350° C. to about 450° C.,for example, at a temperature of about 380° C.

(Step 32)

As in step 12, HCl is supplied to the processing chamber through the gassupply pipe 710 via the nozzle 410 with TiCl₄ supplied to the processingchamber. In this case, an inert gas, such as N2, is continuouslysupplied to the processing chamber through the nozzle 420.

(Step 33)

As in step 13, with HCl supplied to the processing chamber, the supplyof TiCl₄ to the processing chamber is stopped by closing off the valve314 of the gas supply pipe 310, and TiCl₄ is supplied to the vent line610 by opening the valve 614.

(Step 34)

As in step 14, the supply of HCl into the processing chamber is stoppedby closing off the valve 714 of the gas supply pipe 710. In this case,the inside of the processing chamber 201 is exhausted to a pressure ofabout 10 Pa or lower by the vacuum chamber 246 with the APC 243 of thegas exhaust pipe 231 open. Thus, the remaining TiCl₄ is excluded fromthe processing chamber 201. In this case, when an inert gas, such as N₂,is supplied into the processing chamber 201, the remaining TiCl₄ isexcluded more effectively.

(Step 35)

In step 35, NH₃ is supplied under the same conditions as in step 15. NH₃is supplied to the gas supply pipe 320, while the carrier gas (N₂) issupplied to the carrier gas supply pipe 520.

(Step 36)

In step 36, the supply of NH₃ is stopped by closing off the valve 324 ofthe gas supply pipe 320. Also, the processing chamber 201 is exhaustedto an inner pressure of about 20 Pa or lower by the vacuum pump 246 withthe APC valve 243 of the gas exhaust pipe 231 open. Thus, the remainingNH₃ is exhausted from the processing chamber 201.

(Step 37)

In step 37, raising an inner temperature of the processing chamber 201is initiated.

(Step 38)

In step 38, NH₃ is supplied again. NH₃ is supplied under the samecondition as in steps 15 and 25. A temperature of the heater 207 is setsuch that the wafer is maintained at a temperature ranging from about300° C. to about 650° C., preferably, about 400° C. to about 650° C.,for example, at a temperature of about 650° C.

(Step 39)

In step 39, the supply of NH₃ is stopped by closing off the valve 324 ofthe gas supply pipe 320, and an inner temperature of the processingchamber is dropped.

(Step 40)

The inner temperature of the processing chamber is maintained in therange of about 200° C. to about 550° C., preferably, about 350° C. toabout 450° C. In steps 39 and 40, the processing chamber 201 isexhausted to an inner pressure of about 10 Pa or lower with the APCvalve 243 of the gas exhaust pipe 231 open. Thus, the remaining NH₃ isexcluded from the processing chamber 201.

By performing a cycle including steps 31 through 40 at least once apredetermined number of times, a titanium nitride film is formed to apredetermined thickness on the wafer 200. As described above, desorptionof a reaction inhibiting material is promoted by varying the innertemperature of the processing chamber. Also, NH₃ is introduced so as toenable nitridation even if unreacted Ti is dispersed. Although thefourth embodiment describes a case in which a raise in temperature andintroduction of NH₃ are performed simultaneously, the raise intemperature and the introduction of NH₃ may not necessarily be performedsimultaneously.

Although the present embodiment exemplarily describes an example case inwhich HCl serving as a reaction inhibiting material is supplied from theoutside of a processing chamber, the present process is still effectiveeven if HCl generated as a by-product of a reaction in the processingchamber is supplied to the surface of the wafer 200 as in the secondembodiment instead of supplying HCl from the outside of the processingchamber.

In the above-described embodiments, the order of introduction ofrespective gases and the number of times each of the gases is introducedmay be changed without departing from the spirit of the invention.

When HCl serving as a reaction inhibiting material is supplied throughthe same nozzle as NH₃, ammonium nitrate (NH₄Cl) is likely to occur as aby-product. Accordingly, HCl serving as the reaction inhibiting materialis preferably supplied only through the nozzle [nozzle 410] for TiCl₄.However, when a combination of sources which is unlikely to generateby-products is used, the reaction inhibiting material may be suppliedall the nozzles [for example, the nozzles 410 and 420].

According to the present invention, by performing a sequentialfilm-forming process, which is more subdivided than an ALD process,impurities may be inhibited from remaining in the film. Also, since asurface layer of a thin film to be modified may be formed to a smallerthickness, a film quality can be improved more effectively.

In the present embodiments, a portion in which growth of less than oneatomic layer occurs is referred to as a thin film or layer for the sakeof convenience. Here, the growth of less than one atomic layer refers toa case in which the number of atoms per unit area included in a thinfilm grown using a one-time series film forming process is smaller thanthe number of atoms per unit area required for forming one atomic layerof a thin film having an originally estimated plane orientation.

Although a vertical apparatus has been mainly described above, a processof forming a titanium nitride film using at least two different CVDmethods according to the present invention is not limited to thevertical apparatus and may be applied to other apparatuses, such as asingle-type apparatus.

Furthermore, although a vertical thermal CVD apparatus has been mainlydescribed above, formation of a titanium nitride film using at least twodifferent CVD methods according to the present invention is not limitedto a thermal CVD apparatus but may be applied to another apparatus, suchas a plasma CVD apparatus or an optical CVD apparatus.

Furthermore, although an example case in which a titanium nitride filmis formed on a substrate due to a reaction of titanium tetrachloride(TiCl₄) with ammonia (NH₃) has been described, the present invention isnot limited thereto and may be applied to different kinds of films. Inparticular, the present invention may be applied to a metal compoundobtained by adding an element to a nitride serving as a main substance,such as titanium nitride (TiN) or tantalum nitride (TaN).

In addition, although a case where HCl is used as a reaction inhibitingmaterial has been described, the present invention is not limitedthereto and another material may be applied. For example, a halogen gas(chlorine-containing gas) or Cl₂ may be applied.

The present invention provides a semiconductor device manufacturingmethod and a substrate processing apparatus by which a metal film with alow resistivity is formed due to a high density and a low source-induceddopant concentration.

Aspects of the Present Invention

Hereinafter, aspects of the present invention will be added.

(Supplementary Note 1)

According to an aspect of the present invention, there is provided asemiconductor device manufacturing method of forming a film of less thanone atomic layer on a substrate, the method including: (a) supplying asource gas into a processing chamber accommodating the substrate toadsorb the source gas on the substrate; (b) supplying a reactive gasdifferent from the source gas into the processing chamber to cause areaction of the reactive gas with the source gas adsorbed on thesubstrate before the source gas is saturatively adsorbed on thesubstrate; (c) removing an inner atmosphere of the processing chamber;and (d) supplying a modifying gas into the processing chamber to modifythe source gas adsorbed on the substrate.

(Supplementary Note 2)

The reactive gas preferably includes a chlorine (Cl)-containing gas.

(Supplementary Note 3)

Preferably, the source gas includes a metal source, and the modifyinggas includes at least one of an oxygen (O)-containing gas and a nitrogen(N)-containing gas.

(Supplementary Note 4)

Preferably, step (d) includes activating the modifying gas using atleast one of heat, light, and plasma.

(Supplementary Note 5)

Preferably, the method is performed by setting the substrate to atemperature of about 200° C. to about 550° C.

(Supplementary Note 6)

Preferably, the method is performed by setting the substrate to atemperature of about 300° C. to about 450° C.

(Supplementary Note 7)

Preferably, the method is performed by setting the substrate to atemperature equal to or lower than a self-decomposition temperature ofthe source gas.

(Supplementary Note 8)

According to another aspect of the present invention, there is provideda semiconductor device manufacturing method of forming a film of lessthan one atomic layer on a substrate, the method including: (a)supplying a source gas into a processing chamber accommodating thesubstrate to adsorb the source gas of less than one atomic layer on thesubstrate; and (b) supplying a modifying gas for modifying the sourcegas adsorbed on the substrate into the processing chamber.

(Supplementary Note 9)

According to another aspect of the present invention, there is provideda semiconductor device manufacturing method of forming a film of lessthan one atomic layer on a substrate, the method including: (a)supplying a source gas into a processing chamber accommodating thesubstrate to adsorb the source gas on the substrate; (b) supplying areactive gas different from the source gas into the processing chamberto cause a reaction of the reactive gas with the source gas adsorbed onthe substrate before the source gas is saturatively adsorbed on thesubstrate; (c) removing an inner atmosphere of the processing chamber;(d) supplying a modifying gas into the processing chamber to modify thesource gas adsorbed on the substrate; (e) removing the inner atmosphereof the processing chamber; and (f) supplying the modifying gas into theprocessing chamber while activating the modifying gas to modify thesource gas adsorbed on the substrate, wherein steps (a) to (f) aresequentially performed.

(Supplementary Note 10)

According to another aspect of the present invention, there is provideda semiconductor device manufacturing method of forming a film of lessthan one atomic layer on a substrate, the method including: (a)supplying a source gas into a processing chamber accommodating thesubstrate to adsorb the source gas on the substrate; (b) supplying areactive gas different from the source gas into the processing chamberto cause a reaction of the reactive gas with the source gas adsorbed onthe substrate before the source gas is saturatively adsorbed on thesubstrate; (c) removing an inner atmosphere of the processing chamber;and (d) supplying a modifying gas for modifying the source gas into theprocessing chamber while heating the substrate at a second temperaturehigher than the first temperature to modify the source gas adsorbed onthe substrate.

(Supplementary Note 11)

Preferably, the film of less than one atomic layer is formed on thesubstrate by exploiting the fact that a growth rate of the film has apoint of inflection.

(Supplementary Note 12)

A semiconductor device manufactured using one of the methods ofmanufacturing a semiconductor device described in Supplementary Notes 1through 11 is provided.

(Supplementary Note 13)

According to another aspect of the present invention, there is provideda substrate processing apparatus including: a processing chamberconfigured to accommodate a substrate; a source gas supply systemconfigured to supply a source gas into the processing chamber; areactive gas supply system configured to supply a reactive gas differentfrom the source gas into the processing chamber; a modifying gas supplysystem configured to supply a modifying gas into the processing chamber;an exhaust system configured to exhaust an inside of the processingchamber; and a controller configured to control the source gas supplysystem, the reactive gas supply system, the modifying gas supply systemand the exhaust system such that a film of less than one atomic layer isformed on the substrate by performing a process including: (a) supplyingthe source gas into the processing chamber accommodating the substrateto adsorb the source gas on the substrate; (b) supplying the reactivegas into the processing chamber to cause a reaction of the reactive gaswith the source gas adsorbed on the substrate before the source gas issaturatively adsorbed on the substrate; (c) removing an inner atmosphereof the processing chamber; and (d) supplying the modifying gas into theprocessing chamber to modify the source gas adsorbed on the substrate,the source gas being reacted with the reactive gas.

What is claimed is:
 1. A semiconductor device manufacturing methodcomprising: (a) supplying a source gas containing a first element andchlorine to a substrate accommodated in a processing chamber to form anadsorption layer of the source gas on the substrate; (b) supplying achlorine-containing gas having a composition different from that of thesource gas to the substrate while supplying the sources gas before anadsorption of the source gas to the substrate is saturated to suppressthe adsorption of the source gas to the substrate; (c) removing thesource gas and the chlorine-containing gas remaining on the substrate;(d) supplying a modifying gas including a second element to thesubstrate to form a layer comprising the first element and the secondelement on the substrate by modifying the adsorption layer of the sourcegas; and (e) removing the modifying gas remaining on the substrate.
 2. Asemiconductor device manufacturing method comprising: (a) supplying asource gas containing a first element and chlorine to a substrateaccommodated in a processing chamber to form an adsorption layer of thesource gas on the substrate; (b) supplying a chlorine-containing gashaving a composition different from that of the source gas to thesubstrate while supplying the sources gas before an adsorption of thesource gas to the substrate is saturated to suppress the adsorption ofthe source gas to the substrate; (c) removing the source gas and thechlorine-containing gas remaining on the substrate; (d) supplying amodifying gas including a second element to the substrate to form alayer comprising the first element and the second element on thesubstrate by modifying the adsorption layer of the source gas; (e)removing the modifying gas remaining on the substrate; and (f) supplyingthe modifying gas activated by applying light or plasma to desorb thechlorine-containing gas remaining on the layer comprising the firstelement and the second element formed on the substrate.
 3. Asemiconductor device manufacturing method comprising: (a) supplying asource gas containing a first element and chlorine to a substrateaccommodated in a processing chamber while heating the substrate to beat a first temperature to form an adsorption layer of the source gas onthe substrate; (b) supplying a chlorine-containing gas having acomposition different from that of the source gas to the substrate whilesupplying the sources gas before an adsorption of the source gas to thesubstrate is saturated to suppress the adsorption of the source gas tothe substrate; (c) removing the source gas and the chlorine-containinggas remaining on the substrate; (d) supplying a modifying gas includinga second element to the substrate while heating the substrate to be at asecond temperature higher than the first temperature to form a layercomprising the first element and the second element on the substrate bymodifying the adsorption layer of the source gas; and (e) removing themodifying gas remaining on the substrate.
 4. The method of claim 1,wherein the layer comprising the first element and the second element ofless than one atomic layer is formed on the substrate in (d) bycontrolling a growth rate of the layer comprising the first element andthe second element to have a point of inflection.
 5. The method of claim1, wherein the modifying gas comprises a nitridation source.
 6. Themethod of claim 1, wherein the chlorine-containing gas compriseshydrogen chloride gas or chlorine gas.
 7. The method of claim 6, whereinthe chlorine-containing gas comprises hydrogen chloride gas.
 8. Asubstrate processing apparatus comprising: a processing chamberconfigured to accommodate a substrate; a source gas supply systemconfigured to supply a source gas containing a first element andchlorine to the substrate; a chlorine-containing gas supply systemconfigured to supply a chlorine-containing gas having a compositiondifferent from that of the source gas to the substrate; a modifying gassupply system configured to supply a modifying gas containing a secondelement to the substrate; an exhaust system configured to exhaust gasesremaining on the substrate; and a controller configured to control thesource gas supply system, the chlorine-containing gas supply system, themodifying gas supply system and the exhaust system to perform: (a)supplying a source gas containing a first element and chlorine to asubstrate accommodated in a processing chamber to form an adsorptionlayer of the source gas on the substrate; (b) supplying achlorine-containing gas having a composition different from that of thesource gas to the substrate while supplying the sources gas before anadsorption of the source gas to the substrate is saturated to suppressthe adsorption of the source gas to the substrate; (c) removing thesource gas and the chlorine-containing gas remaining on the substrate;(d) supplying a modifying gas including a second element to thesubstrate to form a layer comprising the first element and the secondelement on the substrate by modifying the adsorption layer of the sourcegas; and (e) removing the modifying gas remaining on the substrate.
 9. Asubstrate processing apparatus comprising: a processing chamberconfigured to accommodate a substrate; a source gas supply systemconfigured to supply a source gas containing a first element andchlorine to the substrate; a chlorine-containing gas supply systemconfigured to supply a chlorine-containing gas having a compositiondifferent from that of the source gas to the substrate; a modifying gassupply system configured to supply a modifying gas containing a secondelement to the substrate; an exhaust system configured to exhaust gasesremaining on the substrate; and a controller configured to control thesource gas supply system, the chlorine-containing gas supply system, themodifying gas supply system and the exhaust system to perform: (a)supplying a source gas containing a first element and chlorine to asubstrate accommodated in a processing chamber to form an adsorptionlayer of the source gas on the substrate; (b) supplying achlorine-containing gas having a composition different from that of thesource gas to the substrate while supplying the sources gas before anadsorption of the source gas to the substrate is saturated to suppressthe adsorption of the source gas to the substrate; (c) removing thesource gas and the chlorine-containing gas remaining on the substrate;(d) supplying a modifying gas including a second element to thesubstrate to form a layer comprising the first element and the secondelement on the substrate by modifying the adsorption layer of the sourcegas; (e) removing the modifying gas remaining on the substrate; and (f)supplying the modifying gas activated by applying light or plasma todesorb the chlorine-containing gas remaining on the layer comprising thefirst element and the second element formed on the substrate.
 10. Asubstrate processing apparatus comprising: a processing chamberconfigured to accommodate a substrate; a source gas supply systemconfigured to supply a source gas containing a first element andchlorine to the substrate; a chlorine-containing gas supply systemconfigured to supply a chlorine-containing gas having a compositiondifferent from that of the source gas to the substrate; a modifying gassupply system configured to supply a modifying gas containing a secondelement to the substrate; an exhaust system configured to exhaust gasesremaining on the substrate; and a controller configured to control thesource gas supply system, the chlorine-containing gas supply system, themodifying gas supply system and the exhaust system to perform: (a)supplying a source gas containing a first element and chlorine to asubstrate accommodated in a processing chamber while heating thesubstrate to be at a first temperature to form an adsorption layer ofthe source gas on the substrate; (b) supplying a chlorine-containing gashaving a composition different from that of the source gas to thesubstrate while supplying the sources gas before an adsorption of thesource gas to the substrate is saturated to suppress the adsorption ofthe source gas to the substrate; (c) removing the source gas and thechlorine-containing gas remaining on the substrate; (d) supplying amodifying gas including a second element to the substrate while heatingthe substrate to be at a second temperature higher than the firsttemperature to form a layer comprising the first element and the secondelement on the substrate by modifying the adsorption layer of the sourcegas; and (e) removing the modifying gas remaining on the substrate. 11.The method of claim 2, wherein the layer comprising the first elementand the second element of less than one atomic layer is formed on thesubstrate in (d) by controlling a growth rate of the layer comprisingthe first element and the second element to have a point of inflection.12. The method of claim 2, wherein the modifying gas comprises anitridation source.
 13. The method of claim 2, wherein thechlorine-containing gas comprises hydrogen chloride gas or chlorine gas.14. The method of claim 3, wherein the layer comprising the firstelement and the second element of less than one atomic layer is formedon the substrate in (d) by controlling a growth rate of the layercomprising the first element and the second element to have a point ofinflection.
 15. The method of claim 3, wherein the modifying gascomprises a nitridation source.
 16. The method of claim 3, wherein thechlorine-containing gas comprises hydrogen chloride gas or chlorine gas.